Point is, Microsoft's offering looks like something a small business could use for much longer before needing to upgrade to a paid plan.

Ability to communicate and collaborate with anyone inside or outside your organization, backed by Microsoft's secure, global infrastructure. You can only search the last 10,000 messages, which could be insufficient after a few years or with a larger team.

By comparison, the free version of Slack is limited to 10 app integrations, 5GB of file storage and doesn't permit guest access. "Teams in Microsoft 365 includes everything in the free version plus additional storage, enterprise security, and compliance, and it can be used for your whole organization, regardless of size", Markezich emphasized. The habit-changing tips are powered by MyAnalytics, which has the capability to suggest that users take some time to themselves, or flag that someone is emailing a coworker after hours, in hopes of improving work/life balance, according to the release. Office 365 will use facial detection to automatically detect when particular people are talking, allowing you to jump straight to their portions of the event.

Offering a free version will be an easier way for companies interested in the service to try it out, and could serve as a gateway for more businesses to sign up for the full 365 suite.

What's not included in the free version of Microsoft Teams, but is part of the paid version? Slack has offered a free version since it first arrived on the scene, and looking at Slack's dominance today, it seems like it was a good move.